{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,15]],"date-time":"2026-10-15T17:49:01Z","timestamp":1792086541784,"version":"4.4.0"},"reference-count":27,"publisher":"Public Library of Science (PLoS)","issue":"10","license":[{"start":{"date-parts":[[2026,10,15]],"date-time":"2026-10-15T00:00:00Z","timestamp":1792022400000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"JSPS KAKENHI","award":["JP25K13555"],"award-info":[{"award-number":["JP25K13555"]}]}],"content-domain":{"domain":["www.plosntds.org"],"crossmark-restriction":false},"short-container-title":["PLoS Negl Trop Dis"],"abstract":"<jats:sec id=\"sec001\">\n                    <jats:title>Background<\/jats:title>\n                    <jats:p>\n                      <jats:italic>Treponema pallidum<\/jats:italic>\n                      subsp.\n                      <jats:italic>endemicum<\/jats:italic>\n                      (TEN), the causative agent of bejel, is a nonvenereal treponematosis that occurs mainly in arid regions such as Africa and the Middle East. Recently, sexually transmitted TEN infections have been reported outside endemic regions, but their serological characteristics and treatment responses remain unclear.\n                    <\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec id=\"sec002\">\n                    <jats:title>Methodology\/principal findings<\/jats:title>\n                    <jats:p>\n                      We analyzed 6 genetically confirmed bejel patients and 9 syphilis patients in Japan. Serum treponemal (TP) and non-treponemal (RPR) antibody titers were quantified at baseline and post-treatment using latex agglutination test (LA). The analysis of antibody profiles was performed with an immunoblot assay detecting IgM and IgG antibodies against Tp47, TmpA, Tp17, and Tp15. Phylogenetic analysis based on concatenated\n                      <jats:italic>tp0548<\/jats:italic>\n                      and\n                      <jats:italic>tp0856<\/jats:italic>\n                      sequences identified 6 bejel cases (TEN). Changes in TP and RPR antibody titers following treatment showed no apparent difference between bejel and syphilis groups. In both groups, some IgM antibodies decreased following treatment, while some IgG antibodies increased.\n                    <\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec id=\"sec003\">\n                    <jats:title>Conclusions\/significance<\/jats:title>\n                    <jats:p>The serological profiles and post-treatment changes in antibody titers were similar between bejel patients and syphilis patients. These findings suggest that conventional serological assays developed for syphilis may also be useful for clinical management of bejel, including evaluation of treatment response. This study provides new insight into the diagnosis and serological monitoring of sexually transmitted bejel cases outside endemic areas.<\/jats:p>\n                  <\/jats:sec>","DOI":"10.1371\/journal.pntd.0014756","type":"journal-article","created":{"date-parts":[[2026,10,15]],"date-time":"2026-10-15T17:29:13Z","timestamp":1792085353000},"page":"e0014756","update-policy":"https:\/\/doi.org\/10.1371\/journal.pntd.corrections_policy","source":"Crossref","is-referenced-by-count":0,"title":["Evaluation of treatment-related serological changes in Treponema pallidum subsp. endemicum infection using latex-based immunoassays, with comparison to Treponema pallidum subsp. pallidum"],"prefix":"10.1371","volume":"20","author":[{"ORCID":"https:\/\/orcid.org\/0009-0003-0741-0328","authenticated-orcid":true,"given":"Yu-ki","family":"Deno","sequence":"first","affiliation":[{"name":"Customer Support Center, Diagnostics Division, Sekisui Medical Co., Ltd.","place":["Tokyo, Japan"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Keiyu","family":"Yamamoto","sequence":"additional","affiliation":[{"name":"Customer Support Center, Diagnostics Division, Sekisui Medical Co., Ltd.","place":["Tokyo, Japan"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Mie","family":"Matsumoto","sequence":"additional","affiliation":[{"name":"Customer Support Center, Diagnostics Division, Sekisui Medical Co., Ltd.","place":["Tokyo, Japan"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Toshihiko","family":"Fujikawa","sequence":"additional","affiliation":[{"name":"Research & Development, Sekisui Medical Co., Ltd.","place":["Tokyo, Japan"],"department":["Diagnostic Product Development Department"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Fumiya","family":"Banno","sequence":"additional","affiliation":[{"name":"Osaka Institute of Public Health","place":["Osaka, Japan"],"department":["Division of Microbiology"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Takuya","family":"Kawahata","sequence":"additional","affiliation":[{"name":"Osaka Institute of Public Health","place":["Osaka, Japan"],"department":["Division of Microbiology"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Keiichi","family":"Furubayashi","sequence":"additional","affiliation":[{"name":"Sonezaki Furubayashi Clinic","place":["Osaka, Japan"]}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"340","published-online":{"date-parts":[[2026,10,15]]},"reference":[{"issue":"1","key":"pntd.0014756.ref001","doi-asserted-by":"crossref","first-page":"89","DOI":"10.1128\/CMR.00070-13","article-title":"The endemic treponematoses","volume":"27","author":"L Giacani","year":"2014","journal-title":"Clin Microbiol Rev"},{"issue":"15","key":"pntd.0014756.ref002","doi-asserted-by":"crossref","first-page":"5308","DOI":"10.3390\/jcm14155308","article-title":"The epidemiology of syphilis worldwide in the last decade","volume":"14","author":"F Rosset","year":"2025","journal-title":"J Clin Med"},{"issue":"4","key":"pntd.0014756.ref003","doi-asserted-by":"crossref","DOI":"10.1136\/bmjopen-2025-114337","article-title":"Trends and characteristics of syphilis incidence in Japan: A nationwide claims-based analysis of working-age populations and their dependents, 2016-2023","volume":"16","author":"K Ikeuchi","year":"2026","journal-title":"BMJ Open"},{"key":"pntd.0014756.ref004","doi-asserted-by":"crossref","DOI":"10.1017\/S0950268825100629","article-title":"Risk factors and diagnostic indicators for congenital syphilis: A Nationwide retrospective survey","volume":"153","author":"H Shimizu","year":"2025","journal-title":"Epidemiol Infect"},{"key":"pntd.0014756.ref005","unstructured":"World Health Organization. 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